Effect of differences in proton and neutron density distributions on fission barriers

The neutron and proton density distributions obtained in constrained Hartre e-Fock-Bogolyubov calculations with the Go;my force along the fission paths of Th-232, U-236, U-238, and Pu-240 are analyzed. Significant differences in the multipole deformations of neutron and proton densities are found. Th e effect on potential energy surfaces and on barrier heights is studied und er an additional constraint by imposing similar spatial distributions to ne utrons and protons, as assumed in macroscopic-microscopic models.